1. Field of the Invention
The present invention relates generally to an electrical interrupt device. More particularly, the present invention relates to a thermally activated electrical interrupt device for thermal protection of pumps, related piping and equipment.
2. Description of the Prior Art
A generic thermal switch device is known in the prior art. The general concept provides a thermally reactive material, which causes an electrical circuit to open when the temperature of the thermal material is elevated above a predetermined temperature. Several teachings utilize an actuator, which moves axially based upon an increase in heat to the device, to separate the electrical communication between a cantilevered contact member and a second, stationary contact member. When cooled, the actuator returns to a normal state, closing the electrical communication between the cantilevered contact member and the second, stationary contact member.
The thermal switches are limited whereby, the known devices allow the system to cycle between a thermally alarming and thermally acceptable state. This can continue until recognized and respectfully repaired.
Cantilevered electrical connections can bend, causing different angles required for separation. This can affect repeatability of the activation temperature.
Therefore, a reliable and repeatable thermally activated electrical interrupt switch capable of indicating an over-temperature condition is needed.